Reddit only succeeded because Digg wasn't good enough: it changed in undesirable ways, so users left. How are you going to convince enough redditors that Reddit

Reddit only succeeded because Digg wasn't good enough: it changed in undesirable ways, so users left. How are you going to convince enough redditors that Reddit isn't good enough that a critical mass moves to your platform? I think it's prohibitively difficult, and only a decentralized system will succeed.